FlyinFinn

I'd like to change the crystals in my Vegas radio and receiver to a different channel to avoid conflicts with other Vegas racers at my club. What type of crystals do I need to order? I assume I can order FM, 75 Mhz Futaba crystals , but do I need the short or long ones?

Dan S

The radio in your Vegas is AM and the type of crystals used are 72-11.

FM crystals wont work.

Dan.

piper_chuck

My Feedback: (12)

Note that in the US it's against FCC regulations to change the transmitter crystal on your own. It's only supposed to be done by someone with the equipment and skills to test the transmitter to confirm the signal is on the correct frequency and not spilling over to another frequency. This is the law for the 72 and 75 mhz bands because other users are permitted to use frequencies between our channels. It's also a good practice since changing the crystals can result in significantly lower power output, resulting in less range.

Sean Bowf

Isnt the transmitter crystal soldered to the circuit board in the aquacraft transmitter??

Sean

Dan S

Sean,

no, you can remove the transmitter crystal just by removing the little cap, it comes right out like the receiver.

Dan.

Hydro Junkie

Rather than spend the time and money on the stock radio, go buy yourself a FM system like this one:
http://www2.towerhobbies.com/cgi-bin...=LXNHS1**&P=SM

Sean Bowf

Damn Dan, you're right.

When I pulled out what should be the crystal holder on the transmitter, and saw that it was only a cap, and the crystal was still in the radio..I figured it was soldered to the board. I just pulled one out, and the crystal is socketed... Oh well, I picked up an AM 2PL tranmitter for $17, not knowing that...but the 2PL will allow me to set a throttle limit while my 10 year old is learning to drive the boat...so all is well. Plus, the aquacraft stock radio has let me down...so glad we switched.

I have three 2PLs now (2 AM and 1 FM)... I like them for their simplicity and adjustability.

Sean

FlyinFinn

Whoops! Am, not FM, that's why I asked. Thanks Dan! What is meant by "short crystals"? Can I just get any 72-11 AM crystals?
Jeff.

FlyinFinn

I thought that the 72 means that it is for air use. If not, then what does 72-11 mean? Why, then, does my radio come with a ribbon that says "75 MHz surface use only"? My radio transmitter has a crystal that is stamped 75.590 MHz. Is this AM 75 MHz and not 72 MHz? I'm confused. And, the more that I look at the Tower Hobbies website for the right crystals, the confused I get. I've got a 3PK and I could get a different receiver, which I may do for the Vegas boat. That way I could use the channel I use for my other boats.
Jeff.

Dan S

To quote Ron,

"The 72- used by Futaba has no relation to the frequency band, it's just the numbering system they use on their crystal models."


here's an example of Futaba crystal numbering (nothing to do with what frequency bandwidth you are using);

72-3 AM TX crystal ground frequency ch. 61 thru 90
72-5 AM TX crystal air frequency ch. 11 thru 60
72-7 FM TX & RX crystals air & ground (channel 16 thru 60)
72-9 FM TX & RX crystal (same as 72-7) (-9 only on ch. 11 thru 15)
72-10 FM DC RX crystal air & ground
72-11 AM RX crystal air & ground
72-12 FM RX short crystal

Ron,

you may correct me if I'm wrong I know most crystals are called short but I have never seen a long crystal, I know there is Low and High but as far as I know mainly in the 72Mhz band, example 72Mhz low is channel 11 to 35 and 72Mhz high is channel 36 to 60.

Jeff,
you can use crystals 72-11 (75Mhz AM) anywhere from channel 61-90, and they are called short crystals.

FlyinFinn

Dan and Ron,
Thanks guys, I'm gaining a more clear understanding now. I'm going to go back and read your post again and probably print it out for future reference.
Jeff.

piper_chuck

My Feedback: (12)

Don't use the Tower web site, use this Futaba page: http://www.futaba-rc.com/radioaccys/futl20.html . Once you've figured out the crystal model you need, then go to Tower, or wherever, to order it. Since you've already got the 3PK, I'd suggest buying a different receiver and selling the Vegas transmitter and receiver.